Multi-wall high pressure chambers



July 23, 1968 F. J. FUCHS, JR 3,393,820

MULTI-WALL HIGH PRESSURE CHAMBERS Filed Feb. 5, 1966 5 Sheets-Sheet 1 #vvewroe F. J. FUCHS, JR.

A T TOR/V5 Y July 23, 1968 F- J. FUCHS, JR 3,393,820

MU LLLLLLLLLLLLLLLLLLLLLLLLLL RS eeeeeeeeeeee t3 United States Patent 3,393,820 MULTI-WALL. HIGH PRESSURE CHAMBERS Francis J. Fuchs, Jr., Princeton Junction, NJ assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York j Filed Feb; 3, 1966, Ser. No. 524,739

7 Claims. (Cl. 220-3) thickness is of such size as to require the utilization of 1 excessive masses of metal. Further, with such a thick wall construction, detrimental stress concentrations are encountered due to stress gradients developed across the thickness of the wall.

In order to obviate these difficulties, resort has been made to multi-thin wall construction wherein the stress gradients across each wall thickness are maintained fairly uniform during the generation of the high forming pressures. If each wall abuts the next succeeding wall, the inner wall is still subjected to excessive pressures inasmuch as this inner wall must absorb the total forming pressure before the pressure is transferred to the next succeeding wall section. This difliculty is also encountered in wall constructions of successive convolutions of a single band. A further expedient to obviate the difliculty of working with high pressures includes a wall construction consisting of a plurality of concentric wall members spaced apart so that pressurized fluid may be introduced between the wall sections to counteract the effects of radial expansion; e.g. see applicants co-pending application Serial No. 436,128, filed March 1, 1965. Still another solution to the problem of counteracting the detrimental eifects of high pressures is to provide a chamber surrounded by a series of concentric walls together with successively effective facilities to transfer the counteraction of the radial forces from one wall section to the next, e.g. see applicants co-pending application Ser. No. 512,641 filed Dec. 9, 1965.

An object of this invention resides in a new and improved multi-wall high pressure chamber. V An additional object of the invention is the provision of a multi-wall high pressure forming chamber wherein axial forces generated Within an inner wall are utilized to impress axial forces on the other walls while simultaneously transforming components of these forces into radial forces which oppose the radial expansion of the respective walls.

A further object of the invention resides in the tele scopic arrangement of the wall sections with facilities between each pair of wall sections for converting forces tending to slide one wall over another into forces acting in a transverse direction to oppose forces acting against an interior wall section.

With these and other objects in view, the present inice vention contemplates a high pressure chamber having telescoping wall sections together with facilities. interposed between the wall sections, responding to axial forces within an inner wall section for converting components of these forces into radial forceslwhich oppose the expansion of the inner wall section. Each wall section has spaced inwardly and outwardly extending projections which cooperate to support each other and the interposed facilities. These facilities may comprise ring-like members constructed of resilient material. Upon impression of high pressures to a workpiece within an inner wall section, axial force components are transferred to each succeeding wall section whereupon these wall sections are urged to move in axial directions to compress the resilient material and thus generate force components which oppose the expansion of each preceding wall section.

Other objects and advantages of the present invention will be apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side view partially in section, showing a high pressure forming chamber having a multi-wall construction embodying the principles of the present invention;

FIG. 2 is a side view similar to FIG. 1, particularly illustrating exaggerations of axial displacements of the walls during a high pressure forming operation; and

FIG. 3 is a cross sectional view taken along line 3--3 of FIG. 2 depicting force vectors acting on the walls during the forming operation.

Referring first to FIG. 1, there is shown an inner cylindrical forming block 10 having a cylindrical chamber 11. Chamber 11 is defined by a wall section 12 converging at its lower extremity in a shoulder 13 which, in turn, terminates in an extrusion orifice 14. A billet 16 may be positioned on the shoulder 13 and extruded through the orifice 14, upon application of pressurized fluid to the chamber 11. The extrusion orifice 14 flares out into a receiving chamber 17.

In order to pressurize the fluid within chambers 11 and 17, a pair of rams 18 and 19 are provided. Ram 18 is connected to a piston rod 21 extending into a high pressure fluid cylinder 23. Ram 19 is connected to a piston rod 24 extending into a second high pressure cylinder 26. Suitable seals 27 and 28 are provided to confine the fluid within the chambers 11 and 17 Considering now the facilities which are utilized to compensate for the radial expansion forces generated within the chamber 11, there is provided a plurality of concentric bands 31 and 32 having inwardly projecting flanges 33 and outwardly projecting flanges 34. The wall section 12 is provided with a flange 36 which engages the upper portion of a compressible or pressure transmitting member 37. The lower portion of the compressible member 37 rests against the inner flange 33. This compressible member 37 may be composed of a viscous liquid, neoprene, indium, or other materials which are fluid, elastic, or. resilient under pressure. Similar members 38 and 39 are interposed between the other outwardly and inwardly projecting flanges 33 and 34. Surrounding the outer member 39 is a ring or cylindrical band 41 having an inwardly projecting flange 42 for supporting the outer compressible member 39. The outer and inner rims of the respective flanges abut the inner and outer walls of the forming block 10 and the concentric bands 31, 32, and 41. The

outer cylinder 41 rests-on a stationary support frame43. It may be thus appreciated that the support frame 43 supports the outer cylindrical band 41 and the interposed members 39, 38, and 37, the concentric bands 32 and 31, and the forming block 10.

As illustrated in FIG. 3, the wall 12 and bands 31, 32, and 41 are shown in a cylindrical or circular configuration. It is to be understood that these members may be of other geometrical configuration such as, rectangles or squares.

In operation of the device, the ram 18 is withdrawn and a billet 16 positioned on the shoulder 13 over the extrusion orifice 14. Fluids is introduced into the chambers 11 and 17 and the rams 18 and 19 move toward each other by operation of the fluid cylinders 23 and 26 to pressurize the fluid within the chambers. The fluid is pressurized to such an extent as to render the billet 16 ductile. The ram 19 is then withdrawn resulting in a pressure differential existing between the fluid in the chamber 11 and in the chamber 17. The billet is thereupon extruded through the orifice 14. Obviously, it may be appreciated that other metal forming operations may be performed in chamber 11 such as bending, shaping, etc. Further, it is to be understood that ductile materials, such as copper, may be formed by use of lower pressures.

The pressurized fluid in the chamber 11 has a force component acting in a longitudinal or axial direction as indicated by the vectors A (FIG. 2). These longitudinal forces are transferred through the block to the flange 36 to act against the compressible member 37 as indicated by the force vectors B. Application of compression forces to member 37 result in the exertion of radial forces acting inwardly and outwardly as represented by the force vectors C and D. The pressurized fluid in the chamber 11 acts against the wall section 12 tending to expand this wall section, whereupon this expansion is counteracted by the force vectors C acting inwardly against the outer surface of the wall section. In a like manner, the axial force vectors B results in the application of similar forces to the flanges 33 and 34 which function to apply compression forces to the members 38 and 39 thereby transform ing these axial forces into outwardly and inwardly forces which further act to oppose the expansion of the wall section 12. As the members 37, 38, and 39 are compressed, the forming block 10 and the concentric members 31 and 32 will be urged to move in telescoping fashion to axial positions as shown in exaggeration in FIG. 2. Inasmuch as the outer cylindrical member 41 is resting on a stationary block 43, this member will not move.

With the construction illustrated in the drawing, it is possible to use relatively thin members for wall section 12 and the bands 31, 32, and 41. With the thin wall construction, the pressure gradients across the respective wall members are relatively uniform, thus, avoiding the generation of detrimental stress concentrations on the inner surfaces of these members.

It is to be understood that the above-described arrangements of apparatus and construction of elemental parts are simply illustrative of the application of the principles of the invention and many other modifications may be made without departing from the invention.

What is claimed is:

1. A pressure vessel comprising:

an inner ring providing a pressure chamber;

an outer ring surrounding said inner ring;

said rings mounted for relative axial movement and provided with members defining a space therebetween; and

means provided in said space and for providing lateral support to said inner ring upon said pressure chamber containing a pressurized fluid medium under sufficient pressure to cause relative axial movement between said rings.

2. A pressure vessel comprising:

a pair of concentric cylinders mounted for relative axial movement, and the inner cylinder of said pair pros iding a pressure chamber;

the adjacent walls of said cylinders provided with members defining a space between said cylinders;

a compressible, pressure transmitting member provided in said space; and

upon said pressure chamber containing a pressurized medium under suflicient pressure to cause relative axial movement between said cylinders, said members movable toward each other to compress said compressible member to case said member to exert supporting pressure against said inner cylinder to assist said inner cylinder in containing said pressurized medium.

3. A pressure vessel comprising:

a plurality of concentric cylinders mounted for relative axial movement and the adjacent walls of said cylinders provided with flanges defining a closed space between adjacent cylinders;

each of said spaces containing a compressible, pressure transmitting medium; and

upon relative axial movement between said cylinders,

said flanges for compressing said compressible pressure transmitting media to cause said media to develop and apply radial support force to the inner cylinders of said plurality.

4. A ressure vessel comprising:

concentric rings, spaced apart and relatively movable in axial directions;

a medium in said space between said rings; and

means confining said medium so that relative axial movement between said rings compresses the medium to develop radial support forces.

5. In a high pressure chamber,

an inner hollow cylinder having an inwardly extending shoulder and an outwardly extending flange, said shoulder being axially spaced from said flange,

a support means,

axially compressible and radially expandable means interposed between said support means and said outwardly extending flange for supporting said hollow cylinder, and

means for applying axial forces within said cylinder to act upon said shoulder to urge said cylinder to move relative to said support means and axially compress and radially expand said interposed means.

6. In a high pressure forming chamber,

a cylindrical chamber having an inwardly projecting circumferential section for receiving fluid, said chamber having a radially extending flange,

a plurality of concentric cylinders spaced apart and positioned about said chamber,

each cylinder having an inwardly projecting flange to abut the outer surface of the next succeeding inner cylinder, and an outwardly projecting flange to abut the inner surface of the next succeeding outer cylinder,

a compressible member positioned between each inwardly projecting flange and its associated outwardly projecting flange on the next succeeding inner cylinder, and

means for pressurizing the fluid within the cylindrical chamber to develop axial forces in each of said cylinders which act on said compressible members to impart radial forces on said cylindrical members.

7. In a high pressure chamber,

an inner hollow cylinder having a shoulder projecting into one end of said cylinder and a flange projecting from the outer surface at the opposite end of said cylinder,

a series of concentric bands positioned about and spaced from each other and said outer surface of said cylinder,

extending from one end of the inner surface thereof and an outwardly projecting flange extending from the opposite end of the outer surface thereof, said flanges arranged so that the first inwardly projecting posed means to said supporting means while applying compression forces to said interposed means to exert inwardly directed forces against the outer walls flange is spaced from the flange on the inner cylinder of said cylinder and said inner bands. and each other outwardly extending flange is spaced 5 from the inwardly extending flange on the next succeeding band,

References Cited UNITED STATES PATENTS means for supporting the outer band, means interposed between each outwardly extending 2 E92 flange and each associated inwardly extending flange 10 3243985 4/1966 5 on the next succeeding band for supporting each succeeding inner band and the inner cylinder, and means for applying forces to said shoulder which are successively transferred by the flanges and the inter- RICHARD J. HERBST, Primary Examiner.

G. P. CROSBY, Assistant Examiner. 

4. A PRESSURE VESSEL COMPRISING: CONCENTRIC RINGS, SPACED APART AND RELATIVELY MOVABLE IN AXIAL DIRECTIONS; A MEDIUM IN SAID SPACE BETWEEN SAID RINGS; AND MEANS CONFINING SAID MEDIUM SO THAT RELATIVE AXIAL MOVEMENT BETWEEN SAID RINGS COMPRESSES THE MEDIUM TO DEVELOP RADIAL SUPPORT FORCES. 